The known art describes microfluidic metering apparatuses that use a linear, straight through metering channel within a rotating valve to meter a small volume of fluid. Only two fluidic conduits can be connected via the linear, straight through internal channel in the rotating valve in the prior art. The known art is limited in operational functionality, as it can only transfer the fluid contents of a first fluidic chamber, via the linear metering channel in the rotating valve, to a second fluidic chamber that is directly opposite the first chamber. It may be desirable, however, to transfer fluid contents as between more than two fluidic chambers, which generally cannot be done in conventional systems.
Patents Berndtsson et al. WO98/22797 (published May 18, 1998), Berndtsson WO99/01742 (published Jan. 14, 1999), and related patent applications Rodriguez et al. WO02/089760 A1 (published Nov. 14, 2002), Larsen et al. WO03/104770 A2 (published Dec. 18, 2003), Larsen et al. WO03/104771 A1 (published Dec. 18, 2003), and Larsen WO03/104772 A1 (published Dec. 18, 2003), all disclose conventional microfluidic metering devices. As being representative of such devices, FIG. 1A depicts such a device including a rotating valve 2 with a straight through channel 4 that is in communication with a first pair of opposing fluidic conduits 6 in a housing. The rotating valve is turned through 90 degrees, thus metering a small volume of fluid within the valve, and connecting a second pair of opposing fluidic conduits 8 as illustrated in FIG. 1B.
Berndtsson WO03/044488 A1 (published May 30, 2003) discloses a rotating valve with three straight through channels that all extend directly through the axial centre of the rotating valve. Each straight through channel is rotationally positioned at an angle with respect to the other two straight through channels within the valve. At any one time, two different straight through channels in the rotating valve can connect two different pairs of opposing fluidic conduits in a housing. The two different pairs of opposing fluidic conduits have no means of communicating with each other via the internal channels within the rotating valve. Mototsu EP1535667 A1 (published Jun. 1, 2005) discloses a rotating valve with a concavity formed in the axial direction of the rotating valve and in the outer wall of the rotating valve. The concavity is capable of metering a defined volume of fluid. The rotating valve can join two external conduits that are offset from each other along the axial direction of the rotating valve.
While the prior art discloses the use of linear, straight through channels that can meter a defined volume of fluid and connect two opposing fluidic conduits, they are limited in their ability to carry out a variety of different fluidic operations that require a plurality of fluidic conduits and/or chambers beyond just two, e.g. in conventional devices the entire fluidic contents of a first fluidic chamber can only be transferred to a second fluidic chamber that is directly opposite the first fluidic chamber via the straight through channel in the rotating valve. Other configurations that require transfers of fluid other than between two directly opposite fluidic chambers, including additional chambers beyond two, cannot be performed.